Field of the Invention
This present invention relates to a contoured dressing and a method of making the contoured wound dressing. The method is substantially a continuous in-line method for making a wound dressing.
Description of the Prior Art
Adhesive skin barriers are widely known in the medical field for use in ostomy faceplates, wound dressings, and skin-contacting gaskets or liners of various shapes and sizes, all of which may be generally referred to as hydrocolloid-containing wafers or dressings. Hydrocolloid dressings have a layer of a soft, pliant adhesive material which has both dry and wet tack. It contains a dispersion of hydrocolloid particles capable of absorbing aqueous fluids and of swelling as the absorption takes place. One side of the wafer is covered with a protective film. The opposite side of the barrier layer is protected until use by a release sheet of siliconized paper or other suitable material.
Generally, making a contoured wafer involves a number of steps including: 1) extrusion or injection of a layer of adhesive onto a web; 2) compression of the adhesive into the desired shape and contour; 3) laminating the contoured wafer with a cover film and/or a release sheet; and 4) cutting the dressing from the web. The order of the steps may be different depending on the manufacturing process, however, the goal is to efficiently and cost effectively produce a wound dressing. Several patents discuss methods of making wound dressings or bandages, including U.S. Pat. No. 3,339,546 to Chen; U.S. Pat. No. 4,867,748 to Samuelson; U.S. Pat. No. 5,133,821 to Jensen; U.S. Pat. No. 5,716,475 to Botten et al.; U.S. Pat. No. 5,935,363to Gilman et al.; U.S. Pat. No. 6,093,276 to Leise; Jr., et al. and U.S. Pat. No. 6,309,500 to Jensen et al. Chen '546 discusses a method of mixing the hydrocolloid dough, rolling it through a press for uniformity, flattening with a hydraulic press then covering it with a polyethyelene film. Samuelson '748 discusses a flat press and die casting method for creating a dressing with a beveled edge. Jensen '821 discloses a two step process comprising extrusion of the hydrocolloid followed by compression into the desired contour using a roller having pockets to create the shape. Botten '475 discloses a method using injection and compression molding operation wherein the platen has a mold on its surface. Gilman '363 describes a method of making a contoured hydrocolloid wound dressing using a contoured roller wherein at least two of the steps of contouring and cutting are combined. Leise '276 discloses an in-line operation in which the assembling procedures are integrated with the molding, forming, cutting and other parts-making operations to provide a continuity of automated steps. Jensen '500 discloses and claims a method of manufacturing a wound dressing using a contouring and lamination station, a delaminating station, a driving station and a cutting station. These patents use extrusion and/or injection and compression techniques to form the hydrocolloid as well as a mold for forming the shape. Other than Chen '546, each of the processes have some form of automation; however, each of the processes remains time intensive and costly, particularly since a large amount of the adhesive and the protective cover film and release sheet webbing are discarded as waste.
The required successive processing steps make the manufacturing of wound dressings more complex and time intensive. Additional problems involve keeping the freshly-extruded or injected barrier material from sticking to the contouring roller. The wastage of the adhesive, which is generally expensive, and the cover and release sheet webbing makes the process more expensive. The present invention eliminates these issues.
The present invention uses a gear pump to deposit the adhesive. The adhesive, which is preferably heated, is deposited in a predetermined shaped and thickness onto a protective release paper. The deposited adhesive is then laminated with a protective cover film using a roller that has a predetermined softness and firmness. During the laminating step, the edges of the adhesive are feathered to infinity to form a contoured dressing having a center and a border edge. The fully formed contoured dressing is then cut and packaged. There is no wasting of adhesive, film cover webbing or release sheet webbing, which makes the process more cost effective. There is no need for multiple molds in various shapes and sizes as the adhesive is deposited in the desired shape and the laminating roller completes the contouring. The adhesive does not stick to the roller as the laminating roller applies the film cover on the adhesive as it irons the adhesive. The process is also continuous as the gear pump deposits the adhesive and the roller laminates the adhesive while the silicone release web is moving. This manufacturing method fabricates dressings having various shapes and sizes at high rates of speed in a cost effective and energy efficient manner. The present invention provides an economical method for producing a wound dressing.